Steam-engine-cylinder piston



June 29 1926. 1,590,657 C. UEBELMESSER v STEAM ENGINECYLINDER PISTON Filed March 21, 1925 5 Sheejcs-Shet 1 v auvemtozg v [l MM @51 m flbtomm Jay June 29 1926.

v C. UEBELMESSER STEAM ENGINE CYLINDER PISTON Filed March 21. 1925 3 Sheets-Sheet 2 gvwemtoz Q2; ed a M 1 @51 m flue M4043 /kq c. UEBELMESSER STEAM ENGINE CYLINDER PISTON 'June 29 1926. 1,590,657

Filed Mairch 21, 1925 s Sheets-Sheet s A? a INVENTOR. v

ATTORNEY Patented June 29, 1926.

OF NEW YORK, N. Y.

srnam-nnsrnncymnnnn rrsro v.

Application filed March 21, 1925. Serial No. 17,201,

Asv is well known in the prior state of the art, the compression in a steam cylinder 1ncidental to the return stroke. of the piston involves a loss of power, and particularly so 5 in the uniflow type of engine: and hence the object of my invention is, primarily, to provide means that will automatically relieve excessive compression between the cylinder head and the piston during the so-called compression stroke. To this end my invention consists in the specific construction, combination and arrangement of piston parts herein described and claimcd,a distinctive feature being the provision of twin relief valves therein actuated simultaneously by a common duplex rocker shaft, all as hereinafter fully set forth.

In the accompanying drawings I illustrate a practical embodiment of the essential features of my invention in a piston of the character designated, although I do not limit myself to the identical form and construction of parts and appurtenances shown by way of exemplification, since changes may be made in minor details and equivalent mechanical expedients resorted to, with like results, and without {departing from the spirit and intent of my invention in this respect.

lVith this understanding Fig. 1, represents a side elevation of a piston made in accordance with my invention;

Fig. 2, is a longitudinal section thereof, taken upon plane of line 22, Fig. 4;

Fig. 3, is an end view of the piston shown in Fig. 1, looking in the direction of the arrow 3, Fig. 1;

Fig. 4, is a transverse section of the piston taken upon plane of line 4l, Fig. 2;

Fig. 5, is a side elevation of one of the valve stem bushings;

Fig. 6, is an end elevation thereof;

Fig. 7, is a side elevation of one of the valves;

Fig. 8, is an end elevation thereof;

Fig. 9, is a detail view of one of the valve stems;

Fig. 10, is an elevation thereof taken at right angles to Fig. 9;

Fig. 11, is a sideelevation of the duplex rocker shaft;

Fig. 12, is an end elevation thereof;

Fig. 13, is a sectional elevation of a modification of the piston, taken upon plane of line iii-15, Fig. 14;

Fig. 14, is a sectional elevation taken upon plane of line l b-14, Fig. 13.

The shell of the piston P, is made in two parts, united medially and integrally by screw bolts 7), b, as indicated by dotted lines in Fig. 1, of the drawings, or by any other equivalent mechanical expedient. Mounted in a suitable bearing Z), positioned medially between the two said halves of the piston shell, is a rocker shaft R, formed with a wrist pin '1", at each extremity, said wrist pins 1*, 1", being relatively positioned at right angles to each other, as shown more particularly in Figs. 11 and 12, of the drawings. Slide bearings r, 1*, fit on said wrist pins 1', 1", and these slide bearings r, 9", fit in trans verse recesses s, s, of the cross heads 8, s", of the valve stems S, S, the other extremities of said valve stems carrying the valves V, V. In the arrangement shown in the first ten figures of the drawings the outer extremities of the valve stems S, S, are screw threaded for engagement with the valves V, V, whereas in the modification shown in the last two figures of the drawings said valves V, V, form an integral part of the valve stems S, S, as shown in Fig. 18. In-

either case the valves are connected and controlled simultaneously by the duplex rocker shaft R.

The valves V, V, are essentially cylindrical in type and function, reciprocatable in cylindrical seats 1), p, in the piston shell F, and being formed with pressure relief ducts o, 1;, which, when the valve is in open position as shown at the right hand side of Figs. and 13, admitof communication through the valve between that end of the valve cylinder and the central relief area P, in the piston P, thereby relieving the compression.

Thus constructed and arranged the valves are absolutely noiseless in operation, and are shifted simultaneously by the compression through the medium of the rocker shaft R, in such manner that the opening of one valve closes the other, and vice versa.

The operation of shifting the valves is rendered gradual and uniform, and all impaot or abrupt change of motion obviated by the rock shaft R, acting through the medium of its wrist pins 1", 'r', fitting respectively in the slide hearings 1", 1*, in the transverse recesses s, s, of the cross heads 8, s, on the valve stems S, said wrist pins travelling each in the are of a circle as related to the axis of the rock shaft, and being offset as related to each other as will be understood by reference more particularly to Figs. 11 and 12, of the drawings, thereby avoiding dead centre by counter-balancing each other 5 in this respect. hat I claim as my invention and deslre to secure by Letters Patent, is

In a steam engine piston of the character designated, the combination of twin com- 19 pression relief valves the stems of wh ch are formed with recessed cross heads, slide bearings fitting in said recessed cross heads, and a rock shaft formed With offset Wrist pins-fitting in said slide bearings and arranged to shift said relief valves to alternately open one valve and close the other inultaneonsly, and vice-versa, as and for the purpose set forth.

CHAR-LES UEBELMESSER. 

